Intravenous anesthetics 4

Question 1

Rank each benzodiazepine according to its elimination half-life

Answer 1

midazolam, lorazepam, diazepam

Question 2

What is the mechanism of action of midazolam?

Answer 2

GABA-A agonist

Question 3

What is the onset of action of midazolam?

Answer 3

30-60 seconds

Question 4

What is the duration of action of midazolam?

Answer 4

20-60 minutes

Question 5

What is the clearance of midazolam?

Answer 5

liver

Question 6

What is the active metabolite of midazolam?

Answer 6

1-hydroxymidazolam

Question 7

What is the IV & PO sedation dose of midazolam?

Answer 7

IV: 0.01-0.1 mg/kg
PO: 0.5-1 mg/kg

Question 8

What are the respiratory effects of midazolam?

Answer 8

minimal but synergistic respiratory depression when combined with other sedatives

Question 9

What are the CV effects of midazolam?

Answer 9

minimal

Question 10

What are the CNS effects of midazolam?

Answer 10

anterograde amnesia, anticonvulsant properties
anxiolysis
antispasmodic effects
no analgesia

Question 11

What is remimazaolam indicated for?

Answer 11

induction & maintenance for adults undergoing procedural sedation lasting 30 minutes or less (e.g. endoscopy, bronchosocpy)

Question 12

Patients with ______ are more sensitive to the respiratory depressant effects of midazolam.

Answer 12

COPD

Question 13

What is the IV induction dose of midazolam?

Answer 13

0.1-0.4 mg/kg

Question 14

What respiratory & CV effects does the induction dose of midazolam have?

Answer 14

decreased BP & SVR
respiratory depression

Question 15

How does midazolam affect EEG?

Answer 15

cannot produce isoelectric EEG (propofol and barbiturates can)

Question 16

How does midazolam cause relaxation?

Answer 16

spinally mediated skeletal muscle relaxation (antispasmodic-useful for patient with cerebral palsy)

Question 17

Diazepam undergoes _____

Answer 17

enterophepatic recirculation, which explains why it remains in the body for such a long time

Question 18

Diazepam can be used as an

Answer 18

anticonvulsant and as a preventative measure against emergence deilirum
antispasmodic agent

Question 19

Lorazepam’s amnestic action lasts up to

Answer 19

six hours

Question 20

Lorazepam has a _______ onset.

Answer 20

slow onset which limits its useful as an anticonvulsant

Question 21

What is the relative potency (greatest to least) of the benzodiazepines?

Answer 21

lorazepam>midazolam>diazepam

Question 22

Do any of our anesthetic drugs provide retrograde amnesia?

Answer 22

NO- benzodiazepines do provide anterograde amnesia

Question 23

Propylene glycol is added to diazepam and lorazepam to enhance water solubility which can cause

Answer 23

venous irritation

Question 24

Can midazolam cross the blood-brain barrier?

Answer 24

yes

Question 25

Midazolam has a ______ which gives it hydrophilic and liphophilic properties.

Answer 25

imidazole

Question 26

The adult induction dose of remimazolam is

Answer 26

5 mg IV over 1 minute (can reduce to 2.5-5 mg for sicker patients) maintenance for procedural sedation: may administer 2.5 mg IV over 15 seconds with 2 minutes between each dose

Question 27

Peak sedation for remimazolam occurs

Answer 27

3-3.5 minutes after administration

Question 28

After reconstitution of remimazolam, the single-use vial must be discarded if

Answer 28

not used within 8 hours

Question 29

Remimazolam is rapidly metabolized by

Answer 29

non-specific plasma esterases

Question 30

Although it undergoes organ-independent elimination, patients with severe hepatic dysfunction receiving remimazolam

Answer 30

should recieve a doze reduction

Question 31

Compared to midazolam, remimazolam benefits include

Answer 31

faster onset of action deeper sedation faster recovery

Question 32

Compared to propofol, remimazolam is associated with

Answer 32

less respiratory depression better degree of cardiopulmonary stability

Question 33

Remimazolam is contraindicated in patients with a history of

Answer 33

severe hypersensitivity reaction to Dextran 40

Question 34

Can remimazolam be reversed with flumazenil?

Answer 34

yes

Question 35

A patient is experiencing a prolonged recovery from midazolam sedation. What is the initial dose of flumazenil?

Answer 35

0.2 mg

Question 36

What is the mechanism of action of flumazenil?

Answer 36

A competitive antagonist of the GABA-A receptor

Question 37

Why is flumazenil used?

Answer 37

to reduce the sedative effects of benzodiazepines

Question 38

What is the repeat dose of flumazenil?

Answer 38

0.1 mg may be titrated in 1 minute intervals

Question 39

Side effects of flumazenil include

Answer 39

seizures in benzodiazepine-dependent patients

Question 40

What is an important property of flumazenil?

Answer 40

it has a short duration so repeated doses may be needed to prevent re-sedation

Question 41

What is the duration of action of flumazenil?

Answer 41

30-60 minutes

Question 42

Post-operative benzodiazepine reversal with flumazenil does NOT

Answer 42

increase SNS tone, anxiety or neuroendocrine evidence of stress

Question 43

Flumazenil tends to reverse the _____ effects more than the ______ effects of benzodiazepines

Answer 43

sedative effects; amnestic effects